In general, telecommunication is when two or more entities or units exchange information (i.e., communicate) using technology such as transmitters and receivers. Channels are used to transmit the information either over a wired medium (e.g., signal cables) in the form of electromagnetic signals or a wireless medium (e.g., spectrum) in the form of electromagnetic waves, or a combination of the two. A communication network generally includes transmitters, receivers, and communication channels that transmit the signals from the transmitters to the receivers. Digital communication networks may also include routers that route a message to the correct receiver (e.g., user). Analog communication networks may also include switches that form a connection between two users. Both digital and analog communication networks may include repeaters used to amplify or recreate a signal transmitted over a long distance. The repeaters are usually used to counteract the attenuation (e.g., power loss) that the signal experiences as it is being transmitted.